Selective ethanol extraction from fermentation broth using a silicalite membrane

Influence of fermentation by-products on the purification of ethanol from water using pervaporation

“…It is well known that ethanol fermentation is inhibited by the ethanol product itself, as a consequence, rather low ethanol concentrations are reached in the final fermentation broths (Nomura et al, 2002). This will be even more significant with the increasing interest in the use of lignocellulosic biomass, which was found to be the most promising feedstock for fermentation processes, due to its availability and low cost (Kim and Dale, 2004).…”

“…These include batch-operation of the fermentor, low glucose-to-ethanol yield and no reuse of salts and microorganisms (Nomura et al, 2002). Moreover, energy requirements increase exponentially when ethanol concentration in the feed solution fall below 5 wt.% (Madson and Lococo, 2000).…”

“…Moreover, energy requirements increase exponentially when ethanol concentration in the feed solution fall below 5 wt.% (Madson and Lococo, 2000). Hence, a lot of research was carried out in finding energetically more attractive separation techniques, such as gas/steam stripping (Ezeji et al, 2004), liquidliquid extraction (Bothun et al, 2002), adsorption (Carton et al, 1998) and pervaporation (Bowen et al, 2007;Fadeev et al, 2003;Ikegami et al, 2003;Nomura et al, 2002). These separation technologies for producing fuel grade ethanol from fermentation broths have been extensively reviewed by Vane and compared to the classical distillation process (Vane, 2008).…”

“…The influence of fermentation by-products on membrane performance during pervaporation has already been investigated by several authors (Aroujaliana et al, 2006;Bowen et al, 2007;Fadeev et al, 2003;García et al, 2009;Ikegami et al, 2003;Nomura et al, 2002). Despite this, sometimes contradictory results were observed between different studies and concrete explanations of observed behavior were missing.…”

Preparation of high selectivity silicalite-1 membranes by two-step in situ hydrothermal synthesis

“…Compared with NaA or FAU membrane, FMI (including ZSM-5 and silicalite-1) membranes are still prepared and used within different laboratories up to now, and this may be caused by the following reasons: one is the higher preparation cost compared with NaA or FAU membranes, and another reason is that MFI membranes should be calcined in order to remove the templates, and this often results in the formation of cracks, which decreases the separation performance of the as-synthesized membranes [11]. Furthermore, the low separation performance and low reproducibility may be the main reason to limit the preparation of MFI membranes in largescale [12].An important potential application of hydrophobic silicalite-1 membranes is the separation of organic compounds, such as ethanol, 1-butanol, and other fermentation products, from fermentation broth [13,14]. In this application, silicalite-1 membranes show higher separation performance than polymer membranes [15].…”